Runshen Jiang

Broodiness, egg production, and correlations between broody traits in an indigenous chicken breed

The influence of broodiness on egg production was evaluated, and correlations between the age of the first broody cycle (AFB), duration of first broody cycle, and interval between the end of the first broody cycle and the re-laying of eggs were calculated in Chinese Qingyuan (Q line) chicken. In addition, age at first egg and individual egg production were recorded. From a single hatch, hens were randomly divided into 2 groups, group A (n=576) and group B (n=576). Group A hens were allowed to go through the entire broody cycle, whereas group B hens were treated so as to interrupt the cycle. Mean incidence of broodiness was approximately 15%, with the average AFB at approximately 40 wk (i.e., about 20 wk after the onset of lay). Nonbroody hens produced more eggs than broody and treated hens. However, a higher laying rate during the nonbroody period partially compensated the egg loss from broodiness. Negative correlations (P<0.01) were found between AFB and duration of first broody cycle or interval between the end of the first broody cycle and the re-laying of eggs, indicating that the age of the first broody cycle can be regarded as a phenotypic marker for intensity of broodiness in hens.

Whole-genome resequencing of Xishuangbanna fighting chicken to identify signatures of selection.

BackgroundSelective breeding for genetic improvement is expected to leave distinctive selection signatures within genomes. The identification of selection signatures can help to elucidate the mechanisms of selection and accelerate genetic improvement. Fighting chickens have undergone extensive artificial selection, resulting in modifications to their morphology, physiology and behavior compared to wild species. Comparing the genomes of fighting chickens and wild species offers a unique opportunity for identifying signatures of artificial selection.ResultsWe identified selection signals in 100-kb windows sliding in 10-kb steps by using two approaches: the pooled heterozygosity

Resveratrol alleviates heat stress-induced impairment of intestinal morphology, microflora, and barrier integrity in broilers

({\text{H}}_{\text{p}} )

Density of Contour Feathers and Heat Tolerance in Chickens

(Hp) and the fixation index

RNA-Seq reveals seven promising candidate genes affecting the proportion of thick egg albumen in layer-type chickens

(F_{\text{ST}} )

Effects of Caponization on Expression of Gonadotropin-Releasing Hormone-I and Gonadotropin Subunits Genes in Roosters

(FST) between Xishuangbanna fighting chicken (YNLC) and Red Jungle Fowl. A total of 413 candidate genes were found to be putatively under selection in YNLC. These genes were related to traits such as growth, disease resistance, aggressive behavior and energy metabolism, as well as the morphogenesis and homeostasis of many tissues and organs.ConclusionsThis study reveals mechanisms and targets of artificial selection, which will contribute to improve our knowledge about the evolution of fighting chickens and facilitate future quantitative trait loci mapping.